I'm running Mint 14 with Cinnamon, using the Tout theme. This theme has a light gray gradient on the panel, dark gray text with a white dropshadow behind the text.

I know that typically dropshadows are achieved in GTK themes by drawing the text twice - once with the dropshadow color and then again with the main color, offset by a pixel vertically and/or horizontally. What I'm noticing is that in the clock, sometimes the main text changes, but the dropshadow behind it doesn't. So for example it might be 6:27, but the dropshadow behind the 7 is still the ghost of the 0 from seven minutes ago. Put another way, the clock text says 6:27 but its dropshadow says 6:20.

If I click on the panel and then mouse over the clock, the problem corrects itself temporarily.